Unwrapping Require.JS style AMD declarations.

codemod-amd.js

module.exports = function(file, api) {
  const j = api.jscodeshift;

  const makeModuleExports = (objExpr) => {
    return j.assignmentExpression(
      '=',
      j.memberExpression(
        j.identifier('module'),
        j.identifier('exports')
      ),
      objExpr
    );
  };

  const root = j(file.source);

  // define({foo: true}) -> module.exports = {foo: true};
  root
    .find(j.CallExpression, {callee: {name: 'define'}})
    .filter(p => {
      return j.ObjectExpression.check(p.value.arguments[0]);
    })
    .forEach(p => {
      j(p).replaceWith(makeModuleExports(p.value.arguments[0]));
    });

  // define(function() { return foo }) -> module.exports = foo;
  root
    .find(j.CallExpression, {callee: {name: 'define'}})
    .filter(p => {
      return j.FunctionExpression.check(p.value.arguments[0]);
    })
    .forEach(p => {
      j(p.value.arguments[0])
        .find(j.ReturnStatement)
        .forEach(_p => {
          _p.replace(
            j.expressionStatement(
              makeModuleExports(_p.value.argument)
            )
          );
        });

      const funcBody = p.value.arguments[0].body.body;
      funcBody.forEach(statement => {
        root.__paths[0].value.program.body.push(statement);
      });

      j(p).remove();
    });

  return root.toSource({quote: 'single'});
};